在Python中创建NTFS连接点
有没有办法在Python中创建NTFS连接点?我知道我可以调用在Python中创建NTFS连接点,python,windows,ntfs,junction,Python,Windows,Ntfs,Junction,有没有办法在Python中创建NTFS连接点?我知道我可以调用junction实用程序,但最好不要依赖外部工具。您不想依赖外部工具,但不介意依赖特定环境?我认为您可以安全地假设,如果您运行的是NTFS,那么junction实用程序可能就在那里 但是,如果你的意思是你不想打电话给外部程序,我发现这些东西非常宝贵。它允许您直接从Python调用Windows DLL。我敢肯定,它现在已经出现在标准Python版本中了 您只需找出CreateJunction()(或任何Windows调用的)API调用
junction
实用程序,但最好不要依赖外部工具。您不想依赖外部工具,但不介意依赖特定环境?我认为您可以安全地假设,如果您运行的是NTFS,那么junction实用程序可能就在那里
但是,如果你的意思是你不想打电话给外部程序,我发现这些东西非常宝贵。它允许您直接从Python调用Windows DLL。我敢肯定,它现在已经出现在标准Python版本中了
您只需找出CreateJunction()
(或任何Windows调用的)API调用所在的Windows DLL,然后设置参数和调用。幸运的是,微软似乎并不十分支持它。您可以反汇编SysInternalsjunction
程序或linkd
或其他工具之一,以了解它们是如何实现的
我,我很懒,我只需要调用
junction
作为外部进程:-)您可以使用python win32 API模块,例如
import win32file
win32file.CreateSymbolicLink(srcDir, targetDir, 1)
有关更多详细信息,请参阅
如果您不想依赖于此,您可以始终使用ctypes并直接调用CreateSymbolicLinl win32 API,这是一个简单的调用
下面是使用ctypes的示例调用
import ctypes
kdll = ctypes.windll.LoadLibrary("kernel32.dll")
kdll.CreateSymbolicLinkA("d:\testdir", "d:\testdir_link", 1)
表示支持的最小客户端Windows Vista我在a中回答了这个问题,所以我将把我的答案复制到下面。在写了这个答案之后,我最终只写了一个python模块(如果您可以调用一个只使用ctypes python的模块)来创建、读取和检查可以在中找到的连接。希望有帮助
此外,与使用CreateSymbolicLinkAAPI的答案不同,链接的实现应该适用于支持连接的任何Windows版本。CreateSymbolicLinkA仅在Vista+中受支持
回答:
或者,如果要使用pywin32,可以使用前面提到的方法,要读取,请使用:
from win32file import *
from winioctlcon import FSCTL_GET_REPARSE_POINT
__all__ = ['islink', 'readlink']
# Win32file doesn't seem to have this attribute.
FILE_ATTRIBUTE_REPARSE_POINT = 1024
# To make things easier.
REPARSE_FOLDER = (FILE_ATTRIBUTE_DIRECTORY | FILE_ATTRIBUTE_REPARSE_POINT)
# For the parse_reparse_buffer function
SYMBOLIC_LINK = 'symbolic'
MOUNTPOINT = 'mountpoint'
GENERIC = 'generic'
def islink(fpath):
""" Windows islink implementation. """
if GetFileAttributes(fpath) & REPARSE_FOLDER:
return True
return False
def parse_reparse_buffer(original, reparse_type=SYMBOLIC_LINK):
""" Implementing the below in Python:
typedef struct _REPARSE_DATA_BUFFER {
ULONG ReparseTag;
USHORT ReparseDataLength;
USHORT Reserved;
union {
struct {
USHORT SubstituteNameOffset;
USHORT SubstituteNameLength;
USHORT PrintNameOffset;
USHORT PrintNameLength;
ULONG Flags;
WCHAR PathBuffer[1];
} SymbolicLinkReparseBuffer;
struct {
USHORT SubstituteNameOffset;
USHORT SubstituteNameLength;
USHORT PrintNameOffset;
USHORT PrintNameLength;
WCHAR PathBuffer[1];
} MountPointReparseBuffer;
struct {
UCHAR DataBuffer[1];
} GenericReparseBuffer;
} DUMMYUNIONNAME;
} REPARSE_DATA_BUFFER, *PREPARSE_DATA_BUFFER;
"""
# Size of our data types
SZULONG = 4 # sizeof(ULONG)
SZUSHORT = 2 # sizeof(USHORT)
# Our structure.
# Probably a better way to iterate a dictionary in a particular order,
# but I was in a hurry, unfortunately, so I used pkeys.
buffer = {
'tag' : SZULONG,
'data_length' : SZUSHORT,
'reserved' : SZUSHORT,
SYMBOLIC_LINK : {
'substitute_name_offset' : SZUSHORT,
'substitute_name_length' : SZUSHORT,
'print_name_offset' : SZUSHORT,
'print_name_length' : SZUSHORT,
'flags' : SZULONG,
'buffer' : u'',
'pkeys' : [
'substitute_name_offset',
'substitute_name_length',
'print_name_offset',
'print_name_length',
'flags',
]
},
MOUNTPOINT : {
'substitute_name_offset' : SZUSHORT,
'substitute_name_length' : SZUSHORT,
'print_name_offset' : SZUSHORT,
'print_name_length' : SZUSHORT,
'buffer' : u'',
'pkeys' : [
'substitute_name_offset',
'substitute_name_length',
'print_name_offset',
'print_name_length',
]
},
GENERIC : {
'pkeys' : [],
'buffer': ''
}
}
# Header stuff
buffer['tag'] = original[:SZULONG]
buffer['data_length'] = original[SZULONG:SZUSHORT]
buffer['reserved'] = original[SZULONG+SZUSHORT:SZUSHORT]
original = original[8:]
# Parsing
k = reparse_type
for c in buffer[k]['pkeys']:
if type(buffer[k][c]) == int:
sz = buffer[k][c]
bytes = original[:sz]
buffer[k][c] = 0
for b in bytes:
n = ord(b)
if n:
buffer[k][c] += n
original = original[sz:]
# Using the offset and length's grabbed, we'll set the buffer.
buffer[k]['buffer'] = original
return buffer
def readlink(fpath):
""" Windows readlink implementation. """
# This wouldn't return true if the file didn't exist, as far as I know.
if not islink(fpath):
return None
# Open the file correctly depending on the string type.
handle = CreateFileW(fpath, GENERIC_READ, 0, None, OPEN_EXISTING, FILE_FLAG_OPEN_REPARSE_POINT, 0) \
if type(fpath) == unicode else \
CreateFile(fpath, GENERIC_READ, 0, None, OPEN_EXISTING, FILE_FLAG_OPEN_REPARSE_POINT, 0)
# MAXIMUM_REPARSE_DATA_BUFFER_SIZE = 16384 = (16*1024)
buffer = DeviceIoControl(handle, FSCTL_GET_REPARSE_POINT, None, 16*1024)
# Above will return an ugly string (byte array), so we'll need to parse it.
# But first, we'll close the handle to our file so we're not locking it anymore.
CloseHandle(handle)
# Minimum possible length (assuming that the length of the target is bigger than 0)
if len(buffer) < 9:
return None
# Parse and return our result.
result = parse_reparse_buffer(buffer)
offset = result[SYMBOLIC_LINK]['substitute_name_offset']
ending = offset + result[SYMBOLIC_LINK]['substitute_name_length']
rpath = result[SYMBOLIC_LINK]['buffer'][offset:ending].replace('\x00','')
if len(rpath) > 4 and rpath[0:4] == '\\??\\':
rpath = rpath[4:]
return rpath
def realpath(fpath):
from os import path
while islink(fpath):
rpath = readlink(fpath)
if not path.isabs(rpath):
rpath = path.abspath(path.join(path.dirname(fpath), rpath))
fpath = rpath
return fpath
def example():
from os import system, unlink
system('cmd.exe /c echo Hello World > test.txt')
system('mklink test-link.txt test.txt')
print 'IsLink: %s' % islink('test-link.txt')
print 'ReadLink: %s' % readlink('test-link.txt')
print 'RealPath: %s' % realpath('test-link.txt')
unlink('test-link.txt')
unlink('test.txt')
if __name__=='__main__':
example()
如果您将其放入正在发布的内容中,因为这种形式的符号链接仅在Vista+上受支持。自Python 3.5以来,
\u winapi
模块中有一个函数CreateJunction
import _winapi
_winapi.CreateJunction(source, target)
根据Charles接受的答案,这里是函数的改进(和跨平台)版本(Python2.7和3.5+)
- islink()现在还检测Windows下的文件符号链接(与POSIX等价物一样)
- parse_repasse_buffer()和readlink()现在实际检测正确解码路径所需的重分析点类型(NTFS连接、符号链接或通用)
- readlink()不再因NTFS连接或目录符号链接上的访问被拒绝而失败(除非您确实没有读取属性的权限)
导入操作系统
导入结构
导入系统
如果sys.platform==“win32”:
从Win32文件导入*
从winioctlcon导入FSCTL\u获取\u重新分析\u点
__全部链接=['islink','readlink']
#Win32file似乎没有此属性。
文件\属性\重新分析\点=1024
#它们在win32\lib\winnt.py中定义,但具有错误的值
IO_重新分析_标签_安装_点=0xA0000003#连接
IO_重新分析_标记_符号链接=0xA000000C
def islink(路径):
"""
跨平台islink实现。
支持Windows NT符号链接和重分析点。
"""
如果sys.platform!=“win32”或sys.getwindowsversion()[0]<6:
返回os.path.islink(路径)
返回bool(os.path.exists(path)和GetFileAttributes(path)&
文件\属性\重新分析\点==文件\属性\重新分析\点)
def解析\重新解析\缓冲区(buf):
“”“在Python中实现以下功能:
typedef结构\u重新分析\u数据\u缓冲区{
乌龙重铺标签;
USHORT-repassedatalength;
乌肖特保留;
联合{
结构{
USHORT替代物偏移量;
USHORT替代漆包线;
USHORT PrintNameOffset;
USHORT PrintNameLength;
乌龙旗;
WCHAR路径缓冲区[1];
}符号缓冲区;
结构{
USHORT替代物偏移量;
USHORT替代漆包线;
USHORT PrintNameOffset;
USHORT PrintNameLength;
WCHAR路径缓冲区[1];
}mountpointrepassebuffer;
结构{
UCHAR-DataBuffer[1];
}通用内存缓冲区;
}Dummy名称;
}重新分析数据缓冲区,*准备数据缓冲区;
"""
#看https://docs.microsoft.com/en-us/windows-hardware/drivers/ddi/content/ntifs/ns-ntifs-_reparse_data_buffer
数据={'tag':struct.unpack('ctypes从2.5版开始包含在Python中。junction命令在Vista和Win7上不存在。它已被mklink取代。它作为系统内部工具junction存在。@Charles,一揽子断言很少是个好主意。您可以使用DeviceIoControl
,传递SET\u Repasse\u POINT
,创建联接。很抱歉这样做。我不是说你做不到,我是说Windows API不提供函数调用来在一条指令中创建它…我认为连接是从Win2K开始的,但不是正式的(或者很好的)由MS支持,考虑到缺乏关于如何操作的文档。新的符号链接看起来好多了,特别是因为你可以对文件进行链接,而且(我认为)它们现在可以跨网络。连接不是符号链接的子集。连接仅适用于目录。这个答案不正确,并且为文件创建了符号链接(仅适用于Vista和更高版本)而不是目录的连接点(适用于Windows 2000中的NTFS)和更高版本。不幸的是,在Python中没有真正简单的实现方法。参考Mike McQuaid的评论,投票被否决。我正在寻找连接点,即指向direc的硬链接
import _winapi
_winapi.CreateJunction(source, target)
import os
import struct
import sys
if sys.platform == "win32":
from win32file import *
from winioctlcon import FSCTL_GET_REPARSE_POINT
__all__ = ['islink', 'readlink']
# Win32file doesn't seem to have this attribute.
FILE_ATTRIBUTE_REPARSE_POINT = 1024
# These are defined in win32\lib\winnt.py, but with wrong values
IO_REPARSE_TAG_MOUNT_POINT = 0xA0000003 # Junction
IO_REPARSE_TAG_SYMLINK = 0xA000000C
def islink(path):
"""
Cross-platform islink implementation.
Supports Windows NT symbolic links and reparse points.
"""
if sys.platform != "win32" or sys.getwindowsversion()[0] < 6:
return os.path.islink(path)
return bool(os.path.exists(path) and GetFileAttributes(path) &
FILE_ATTRIBUTE_REPARSE_POINT == FILE_ATTRIBUTE_REPARSE_POINT)
def parse_reparse_buffer(buf):
""" Implementing the below in Python:
typedef struct _REPARSE_DATA_BUFFER {
ULONG ReparseTag;
USHORT ReparseDataLength;
USHORT Reserved;
union {
struct {
USHORT SubstituteNameOffset;
USHORT SubstituteNameLength;
USHORT PrintNameOffset;
USHORT PrintNameLength;
ULONG Flags;
WCHAR PathBuffer[1];
} SymbolicLinkReparseBuffer;
struct {
USHORT SubstituteNameOffset;
USHORT SubstituteNameLength;
USHORT PrintNameOffset;
USHORT PrintNameLength;
WCHAR PathBuffer[1];
} MountPointReparseBuffer;
struct {
UCHAR DataBuffer[1];
} GenericReparseBuffer;
} DUMMYUNIONNAME;
} REPARSE_DATA_BUFFER, *PREPARSE_DATA_BUFFER;
"""
# See https://docs.microsoft.com/en-us/windows-hardware/drivers/ddi/content/ntifs/ns-ntifs-_reparse_data_buffer
data = {'tag': struct.unpack('<I', buf[:4])[0],
'data_length': struct.unpack('<H', buf[4:6])[0],
'reserved': struct.unpack('<H', buf[6:8])[0]}
buf = buf[8:]
if data['tag'] in (IO_REPARSE_TAG_MOUNT_POINT, IO_REPARSE_TAG_SYMLINK):
keys = ['substitute_name_offset',
'substitute_name_length',
'print_name_offset',
'print_name_length']
if data['tag'] == IO_REPARSE_TAG_SYMLINK:
keys.append('flags')
# Parsing
for k in keys:
if k == 'flags':
fmt, sz = '<I', 4
else:
fmt, sz = '<H', 2
data[k] = struct.unpack(fmt, buf[:sz])[0]
buf = buf[sz:]
# Using the offset and lengths grabbed, we'll set the buffer.
data['buffer'] = buf
return data
def readlink(path):
"""
Cross-platform implenentation of readlink.
Supports Windows NT symbolic links and reparse points.
"""
if sys.platform != "win32":
return os.readlink(path)
# This wouldn't return true if the file didn't exist
if not islink(path):
# Mimic POSIX error
raise OSError(22, 'Invalid argument', path)
# Open the file correctly depending on the string type.
if type(path) is type(u''):
createfilefn = CreateFileW
else:
createfilefn = CreateFile
# FILE_FLAG_OPEN_REPARSE_POINT alone is not enough if 'path'
# is a symbolic link to a directory or a NTFS junction.
# We need to set FILE_FLAG_BACKUP_SEMANTICS as well.
# See https://docs.microsoft.com/en-us/windows/desktop/api/fileapi/nf-fileapi-createfilea
handle = createfilefn(path, GENERIC_READ, 0, None, OPEN_EXISTING,
FILE_FLAG_BACKUP_SEMANTICS | FILE_FLAG_OPEN_REPARSE_POINT, 0)
# MAXIMUM_REPARSE_DATA_BUFFER_SIZE = 16384 = (16 * 1024)
buf = DeviceIoControl(handle, FSCTL_GET_REPARSE_POINT, None, 16 * 1024)
# Above will return an ugly string (byte array), so we'll need to parse it.
# But first, we'll close the handle to our file so we're not locking it anymore.
CloseHandle(handle)
# Minimum possible length (assuming that the length is bigger than 0)
if len(buf) < 9:
return type(path)()
# Parse and return our result.
result = parse_reparse_buffer(buf)
if result['tag'] in (IO_REPARSE_TAG_MOUNT_POINT, IO_REPARSE_TAG_SYMLINK):
offset = result['substitute_name_offset']
ending = offset + result['substitute_name_length']
rpath = result['buffer'][offset:ending].decode('UTF-16-LE')
else:
rpath = result['buffer']
if len(rpath) > 4 and rpath[0:4] == '\\??\\':
rpath = rpath[4:]
return rpath